Archived posting to the Leica Users Group, 1998/09/20
[Author Prev] [Author Next] [Thread Prev] [Thread Next] [Author Index] [Topic Index] [Home] [Search]Here are the plans for making the adaptor: PARTS NEEDED: 55mm-52mm step-down adaptor 52mm filter (thin-type...Nikons are good), type/condition of glass doesn't matter 52mm adaptor ring for Cokin "A" (small) filter holder Loctite-271 "RED" (permanent thread-locking fluid) TOOLS NEEDED: Bench grinder or Dremel tool with abrasive stone capable of grinding aluminum Ultra-fine grit sandpaper or (impregnated-rubber) polishing wheel for above motor INSTRUCTIONS: 1. Place flat side of one of the Leica Universal Polarizer adaptors against the flat side of the Cokin ring, making sure it is exactly centered. 2. Holding them tightly in place, using the Leica ring as a template, trace a scribe line on the Cokin ring using a sharp point such as an awl or the edge of a small screwdriver. 3. Grind the outer circumference of the Cokin ring evenly to the scribe line. The outer diameter of the Cokin ring should now be the same as the Leica ring. 4. Smooth the ground surface with ultra-fine sandpaper or the Dremel impregnated rubber polishing wheel. NOTE: THE RING WILL REALLY HEAT UP ENOUGH TO BURN YOUR FINGERS! HOLD IT WITH GLOVES AND KEEP A BOWL OF WATER NEARBY TO DIP THE RING IN FREQUENTLY TO COOL IT OFF! 5. Remove glass from 52mm filter. (Some of them you can unscrew a retaining ring, some you've got to wrap in a heavy paper towel and hit with a hammer. If you do that, be careful not to get glass pieces in your fingers!) 6. Place a very small amount of Loctite on MALE threads of 52mm (glass-less) filter and screw it into the 55-52 stepdown ring. (BE CAREFUL NOT TO GET ANY LOCTITE ON THE MALE 55mm THREADS UNLESS YOU WANT IT PERMANENTLY ATTACHED TO YOUR LENS!!!!) 7. Place very small amount of Loctite on threads of Cokin ring and screw it into front (female) threads on glass-less 52mm filter. 8. You should now see (side view) a flat flange which will insert into the Leica polarizer, followed by a narrow spacer (the glass-less 52mm filter, needed to clear the Polarizer retaining "wall" and screw) followed by the 55mm male threads which will screw into the lens. 8. Let it cure overnight. The Loctite assures that all components will not come apart individually.